Handle stepFree option consistently

... for ways in the base TranversalPermissionLabeler (by passing the TransportNetworkConfig files as an argument), and for nodes with kerb tags

Also, reduce duplicate code

Author: ansoncfit

src/test/java/com/conveyal/r5/labeling/TestPermissionsLabeler.java

@@ -1,5 +1,7 @@
 package com.conveyal.r5.labeling;
 
+import com.conveyal.r5.analyst.cluster.TransportNetworkConfig;
+
 /**
  * This is used for tests. It adds new highway tag highway=nobikenoped which forbids cycling and walking. But allows other things.
  * Created by mabu on 27.11.2015.
@@ -8,4 +10,8 @@ public class TestPermissionsLabeler extends USTraversalPermissionLabeler {
     static {
         addPermissions("highway=nobikenoped", "access=yes;bicycle=no;foot=no");
     }
+
+    public TestPermissionsLabeler () {
+        super(null);
+    }
 }